NUCLEO-L073RZ/NUCLEO-L053R8 Dev Board Support

[zephyrbot]

Reported by Dhamodharan Krishnan:

Would be great if we can add support for Nucleo-L0 boards as it supports very low power application.

NUCLEO-L073RZ
NUCLEO-L053R8

(Imported from Jira ZEP-2142)

[zephyrbot]

by Kumar Gala:

Is there any reason you can't contribute support for these platforms?

[zephyrbot]

by Dhamodharan Krishnan:

I am very new to this platform as I was from Arduino and mbed application side. Moreover, I haven't worked on any ports.
Contributing currently towards testing some of the drivers e.g. UART.

[nashif]

both boards are in the tree already.